points. move the call to uvm_pager_realloc_emerg() to after we
drop the uvm_fpageqlock, since it may be taken again in uvm_km_alloc().
fixes LOCKDEBUG crashes with the previous change.
- Reorganize locking in UVM and provide extra serialisation for pmap(9).
New lock order: [vmpage-owner-lock] -> pmap-lock.
- Simplify locking in some pmap(9) modules by removing P->V locking.
- Use lock object on vmobjlock (and thus vnode_t::v_interlock) to share
the locks amongst UVM objects where necessary (tmpfs, layerfs, unionfs).
- Rewrite and optimise x86 TLB shootdown code, make it simpler and cleaner.
Add TLBSTATS option for x86 to collect statistics about TLB shootdowns.
- Unify /dev/mem et al in MI code and provide required locking (removes
kernel-lock on some ports). Also, avoid cache-aliasing issues.
Thanks to Andrew Doran and Joerg Sonnenberger, as their initial patches
formed the core changes of this branch.
so that VA and PA have the same color. On a page fault, choose a physical
page that has the same color as the virtual address.
When allocating kernel memory pages, allow the MD to specify a preferred
VM_FREELIST from which to choose pages. For machines with large amounts
of memory (> 4GB), all kernel memory to come from <4GB to reduce the amount
of bounce buffering needed with 32bit DMA devices.
Maintain an array of pointer to struct vm_physseg, instead of struct
array. So that VM subsystem can take its pointer safely. Pointer
to this struct will replace raw paddr_t usage in the future.
Dynamic removal is not supported yet.
Only MD data structure changes, no kernel bump needed.
Tested on i386, amd64, powerpc/ibm40x, arm11.
vm_page *) "reverse" lookup code from uvm_page.h to uvm_page.c, to
help migration to not do that.
Likewise move per-page metadata (struct vm_page *) -> physical
address "forward" conversion code into *.c too. This is called
only low-layer VM and MD code.
lookup code from uvm_page.h to uvm_page.c.
This code is used by some pmaps to lookup per-page state (PV) from
per-segment metadata (struct vm_physseg). This is not needed if
UVM looks up physical segment once in fault handler, then directly
passes it to pmap. This change helps transition to that model.
The only users of vm_physseg_find() are pmap_motorola.c and
powerpc/ibm4xx/pmap.c.
Tested By: Compiling and running powerpc/ibm4xx/pmap.c
(evbppc/conf/OPENBLOCKS266)
1. Fix inverted node order, so that negative value from comparison operator
would represent lower (left) node, and positive - higher (right) node.
2. Add an argument (i.e. "context"), passed to comparison operators.
3. Change rb_tree_insert_node() to return a node - either inserted one or
already existing one.
4. Amend the interface to manipulate the actual object, instead of the
rb_node (in a similar way as Patricia-tree interface does).
5. Update all RB-tree users accordingly.
XXX: Perhaps rename rb.h to rbtree.h, since cleaning-up..
1-3 address the PR/43488 by Jeremy Huddleston.
Passes RB-tree regression tests.
Reviewed by: matt@, christos@
numbers. Using ptoa() will cast to vaddr_t, which might no be adequate
for architectures where sizeof(paddr_t) > sizeof(vaddr_t) (like i386 PAE).
- small fix inside AGP heuristics to avoid masking high order bits for
systems with more than 4GB.
Reviewed by bouyer@.
See also http://mail-index.netbsd.org/tech-kern/2010/02/22/msg007373.html
was not anymore/yet on the freelist and uvm_fpageqlock was not held
-clear PQ_FREE while the page is in the works of pageidlezero
This avoids that the DMA memory allocator (pglistalloc) grabs a page
which is not on the freelist, leading to a diagnostic panic (with DEBUG)
or freelist corruption. (mostly on X server activation after a VT
switch or suspend/resume because this can allocate megabytes of AGP
memory)
This might fix PR port-i386/38989 by Alan Barrett (in case this was
a multiprocessor).
serves as less of a barrier these days. Restrict provision of kernel reserve
pages to kmem and one of these cases:
- doing a NOWAIT allocation
- caller is a realtime thread
- caller is a kernel thread
- explicitly requested, for example by the pmap
use both types of list.
- Make page coloring and idle zero state per-CPU.
- Maintain per-CPU page freelists. When freeing, put pages onto the local
CPU's lists and the global lists. When allocating, prefer to take pages
from the local CPU. If none are available take from the global list as
done now. Proposed on tech-kern@.
- Use high and low water marks to try and reduce power consumption.
- Do trylock on uvm_fpageqlock, and bail if we can't get it.
- Only run on one CPU at a time.
